A two-gene phylogeny shows the lichen genus Niebla (Lecanorales) is endemic to the New World and does not occur in Macaronesia nor in the Mediterranean basin.

The generic segregates of the widespread fruticose genus Ramalina (mostly based on empirical data on morphology, cortex anatomy and secondary metabolites) are studied using maximum parsimony, maximum likelihood and Bayesian analyses of nuclear LSU and ITS sequences. The species examined include the three species aggregates within Niebla from the western coasts of North America, all species except one assumed to belong to the same genus from Macaronesia and the Mediterranean basin, the type species of Dievernia and Ramalina, and representatives of the genus Fistulariella. The genus Niebla is strongly supported when restricted to species from the New World, and all species referred to it from Macaronesia and the Mediterranean basin belong to Ramalina (R. bourgeana, R. crispatula, R. cupularis, R. hamulosa, R. portosantana, R. rosacea, R. subwebbiana and R. webbii). No support is found for the genera Dievernia and Fistulariella. The internal topology of the large genus Ramalina is unresolved and needs further studies.